Apparatus for driving lockbolts and the like



Sept. 26, 1961 G. J. VAN HECKE 3,001,548

APPARATUS FOR DRIVING LOCKBOLTS AND THE LIKE Filed June 10, 1959 3Sheets-Sheet 1 INVENTOR- fieorye .7, K477 flea/1e,

7 Sept. 26, 1961 APPARATUS FOR DRIVING LOCKBOLTS AND THEVLIKE Filed June10, 1959 3 Sheets-Sheet 2 WWW INVENTQR.

50 [:85 V56 /4 George J. 14 ficie APPARATUS FOR DRIVING LOCKBOLTS ANDTHE LIKE Filed June 10, 1959 Sept 26, 1961 G. J. VAN HECKE 5Sheets-Sheet 3 Patented Sept. 26, 1961 This invention relates generallyto apparatus for driving lockbolts and the like and more particularly toan improved control unit for controlling operation of the drivingapparatus.

It is desirable, in apparatus for driving lockbolts and similarfasteners, to have an available control unit which can be connected toany suitable source of current and hydraulic power so that a hydraulicfastener applying tool can be operated and controlled by the unit. Thecontrol unit of this invention controls the supply of fluid to the toolso as to prevent excessive pressures in the tool and to limit thepressures to only those required for satisfactory tool operation. It isan object of the present invention, therefore, to provide a control unitcapable of performing these functions and which is of a compact portableconstruction by virtue of the inclusion in the unit of a compactmultiple function hydraulic valve unit.

A further object of this invention is to provide a control unit which issimple in construction, economical to manufacture and efiicient inoperation in controlling the supply of fluid pressure to a fastenerapplying tool.

Further objects, features and advantages of this invention will becomeapparent from a consideration of the following description, the appendedclaims and the accompanying drawing in which:

FIGURE 1 is an elevational view of the control unit of this invention,shown in assembly relation with a fastener applying tool, with someparts broken away and other parts shown in section for the purpose ofclarity;

FIG. 2 is an enlarged sectional view taken substantially along the line22 in FIG. 1;

FIGURE 2a is a fragmentary view of the portion designated 2a in FIGURE 2with the valve shown therein in a position off the associated valveseat;

FIG. 3 is a sectional view looking along the line 33 in FiG. 2;

FIG. 4 is a sectional view looking the line 4-4 in FIG. 2;

FIG. 5 is a sectional View, illustrated similarly to FIG. 4, showing thevalve spool in a moved position relative to the position shown in FIG.4; and

FIG. 6 is a diagrammatic view of the hydraulic circuit in the apparatusof this invention.

With reference to the drawing, the control unit of this invention,indicated generally at 10, is illustrated in FIG. 1 in assembly relationwith a fastener applying tool 12. The tool 12 includes a nose assembly14 having gripping jaws 16 associated with a piston 18 which is mountedfor reciprocal movement in a cylinder portion 20 of the tool 12. Adepending handle 22 on the tool 12 carries a trigger 24 mounted foroperating a switch 26 for a purpose to appear presently.

When fluid under pressure is supplied through a passage 28, hereinafterreferred to as the pressure passage, to the cylinder portion 20, thepiston 18 is moved in a direction to move the jaws 16 inwardly of thenose assembly 14. Such movement, when the jaws have been applied to afastener, is effective to either fully or partially set the fastener.The piston 18 has a valve member 30 extended therethrough and urged by aspring 34 toward a seat 32 formed on the piston. Movement of the piston13 toward the rear end of cylinder portion 20 is terminated byengagement of the valve member 30 with a stop memsubstantially along ber36 which moves the valve member 30 oh? the seat 32 so as tofluid-communicate opposite sides of the piston 18. When fluid underpressure is supplied to the cylinder portion 20 through a passage 38 inthe handle, hereinafter referred to as the return passage, the fluid isapplied to the opposite side of the piston so that the piston is movedin a return direction to move the jaw 16 in a direction outwardly of thenose assembly 14 for application to another fastener.

The switch 26 is electrically connected to the unit 10 by a conductor 40which is plugged into a socket42 on a casing 44 for the unit 10. Thepressure passage 28 is connected by a flexible line 46 to the unit 10and the return passage 38 is connected by a corresponding flexible line48 to the unit 10.

The unit 10 consists of the casing 44 which is provided with a handle 47to facilitate transport thereof, and a hydraulic valve unit 49, astep-down transformer 50, and a relay 52, which are mounted on andenclosed within the casing 44. The valve unit 49 consists of a valvebody 54 (FIGS. 2, 3 and 4) which is provided with a main fluid passage56 connected through a transverse passage 62 to a pump, indicateddiagrammatically at 58 in FIG. 5 and illustrated as being driven by amotor 60.

A tank 64 is connected by a line 66 to the pump 58 and by a line 68 tothe valve body 54. The line 68 is connected to a pair of passages 70 and72 in the valve body 54 which communicate with the main passage 56 onopposite sides of the pump passage 62.

The pressure line 46 communicates through a passage (not shown) withpassages 74 and 76 which connect with the main passage 56 at a positionbetween the supply passage 62 and the tank passage 72. The return line48 communicates through a passage (not shown) with passages 78 and 80which connect with the main passage 56 at a position between the supplypassage 62 and the tank passage 70. A valve spool member 82 is mountedfor reciprocating movement in the main passage 56 and is provided withlands 84, 86 and 88 which are of a diameter to flt within reducedportions 90, 92, 94, 96 and 98 of the main passage 56 in a substantiallyfluid-tight relation therewith.

The spool member 82 is connected at one of its ends to a solenoidassembly 100 mounted on the valve body 54. The opposite end of the spool82 is formed with an axial cavity 101 in which one end of a spring 102is positioned and the opposite end of which is retained on the body 54by a cap 104. The spring 102 continually exerts a force on the spoolmember 82 which urges the spool member 82 upwardly as shown in FIG. 2.When the solenoid 100 is deenergized, the spring 102 maintains the spoolmember 82 in the position shown in FIG. 2 in which a flange 1% at thespring-urged end of the spool engages a shoulder 108 on the body 54. Inthis position of the spool member 82 the land 86 is positioned in thepassage portion 24 so as to block communication of the pump passage 62with the pressure passage 80 which is in communication with the tankpassage 70. The land 84 is positioned in the main passage portion so asto block communication of the tank passage 72 with the return passage 76which communicates through the main passage 56 with the pump passage 62.

When the solenoid is energized, the spool 82 is moved to a positionshown in FIG. 5 in which the flange 106 engages the cap 104 and the land86 is within the passage portion 92 so as to block communication of thereturn passage 76 with the pump passage 62 which is then incommunication with the pressure passage 80. The land 88 is positioned inthe cylinder portion 6 so as to block communication of the tank passage70 with the pressure passage 78. The tank passage 72 communicates withthe return passage 76 through the main passage 56,

A bore 110 in the body 54 parallel to the main passage 56 communicatesthrough a passage 112 with the tank line 68. An idler valve member 114is mounted in the bore 110 for reciprocating movement and is urged by aspring 116, which is retained in the bore 110 by a cap 118, is adownward direction as viewed in FIG. 2. Aplug member 120 inserted in thelower end of the bore 110 has a passage 122 which connects the bore 110with the return passage 74. The valve member 114 has a reduced andtapered lower end portion 124 which is urged by the spring 116 into aseated position on the plug 120 in one end of the passage 122. Becausethe portion 124 which seats on the end of the passage 122 is of areduced size, a greater pressure is required to move the valve member114 ofl its seat than is required to maintain the valve member 114 in aposition oif its seat.

A second bore 130, which is perpendicular to and is located to one sideof the main passage 56, communicates through a passage 132 with the bore110 and through a passage 134, with main passage 56. As shown in FIG. 3,the passage 134 intersects the main passage 56 at a positiondiametrically opposite the pump passage 62. A relief valve member 136 ismounted for reciprocal movement in the passage 130 and is urged by aspring 138, that is held on the body 54 by a retainer cap 139, toward aposition seated in one end of a passage 140 formed in a plug memher 142inserted in the bore 130. The plug passage 140 communicates with thepassage 134 so that when the relief valve member 136 is moved off itsseat, the pump passage 62 communicates with the tank passage 112.

In the use of the control unit 10, the conduit 40 is plugged into thesocket 42 and the transformer 50 and relay 52 are connected to a sourceof 110 volt current. The transformer 50 steps this voltage down to about24 volts to reduce the electrical hazard at the tool 12 and the relay 52has contacts which are closeable to provide for the necessary 110 voltsto operate the solenoid assembly 100. When the trigger member 24 isoperated to close the switch 26, the solenoid assembly 100 is energizedto move the spool member 82 to the position illustrated in FIG. 5 sothat fluid at a relatively high pressure flows from the pump 58, througha filter 141, through the pump passage 62, the main passage 56, thepressure passages 78 and 80, the pressure line 46, and the pressurepassage 28 in the tool 12 to the cylinder portion to move the toolpiston 18 in a direction to move the jaws 16 inwardly of the tool. Fluidin the cylinder portion 20 on the opposite side of the piston 18 isforced through the return passage 38, and the return line 48 to thevalve unit 49. This fluid enters the valve unit 49 through the passages74 and 76 and flows to the main passage 56 from which it flows throughthe tank passage 72 to the tank line 68.

During operation of the tool 12, in the event the fluid pressure risesabove a predetermined safe limit at any time, due to an abnormally highbreakneck strength of the fastener, or for any other reason, the Valvemember 136 will be moved off its seat on the plug 142 so as tocommunicate the pump passage 62 with the tank passage 112 to therebyreduce the fluid pressure in the cylinder portion 21).

When the trigger 24 is released, so that the switch 26 is opened, thesolenoid assembly 100 is deenergized so that the spring 102 is efiectiveto move the spool member 82 to the position illustrated in FIG. 2. Inthis position, fluid from the pump passage 62 is supplied through themain passage 56 to the return passage 74 from which it flows through thereturn line 48 and the return passage 38 in the tool 12 to the cylinderportion 20 for moving the piston 18 in a direction to move the jaws 16outwardly of the tool 12 to a position in which they can be applied toanother fastener. Since the return passage 74 communicates through thepassage 122 with the idler valve member 114, and the fluid pressure inthe pump passage 62 is at the same high pressure required for operationof the tool 12, the fluid in the passage 74 is at a sufiiciently highpressure to move the valve member 114 off its seat to the broken lineposition shown in FIG. 2, which position is more clearly shown in FIGURE2a, so that the tank passage 112 is in leaking communication with thepassage 122. Consequently, the fluid pressure in the return passage 74drops to only the pressure required to maintain the valve member 114 inan unseated position in which fluid leaks past valve member 114 intopassage 112. This pressure is substantially below the pressure utilizedto move the piston 18 in a working direction but is entirely adequate tomove the piston in a return direction. As a result of this arrangement,the tool 12 is not subjected to unnecessarily high fluid pressuresduring the return of the piston 18 to thereby improve the service lifeof the tool 12.

From the above description, it is seen that the control unit 10 of thisinvention is connectible to the tool 12 and to a suitable source ofelectrical power and fluid pressure so as to provide for a controlledoperation of the tool 12. One of the main advantages of the control unit10 is the fact that it is of a compact construction and thus readilyportable. The valve unit 48 is in effect three different valvesincorporated in a single valve body. It includes the idler valve member114, the relief valve member 136 and the control valve having the spool82. This construction of the valve member 48 reduces its size andthereby contributes to the compactness of the unit 10.

Although the invention has been described with respect to a preferredembodiment thereof, it is to be understood that it is not to be solimited, since changes can be made therein which are Within the scope ofthe invention as defined by the appended claims.

What is claimed is:

1. In apparatus for driving lockbolts and the like which includes ahydraulically operated tool; a valve body having an inlet for fluidunder pressure and a return to tank outlet, a first valve member mountedin said body for movement between two positions for controlling the flowof fluid to said tool, a second valve member mounted in said body andfluid-communicated with said first valve member and said inlet in onlyone of said positions, said second valve member communicating with saidoutlet and being movable to an open position by a fluid pressure above apredetermined pressure exerted thereon, and a pressure relief valvemember mounted on said body and communicating with said inlet in bothpositions of said first valve member.

2. In apparatus for driving lockbolts and the like which includes ahydraulically operated tool; a valve body having an inlet for fluidunder pressure and a return to tank outlet, at first valve membermounted in said body for movement between tWo positions for controllingthe flow of fluid to said tool, a solenoid assembly mounted on said bodyand connected to said first valve member for moving the valve member toone of said positions, a second valve member mounted in said body andfluid-communicated With said first valve member and said inlet in onlyone of said positions of said first valve member, said second valvemember communicating with said outlet and being movable to an openposition by a fluid pressure above a predetermined pressure exertedthereon, and a pressure relief valve member mounted on said body andcommunicating with said inlet in both positions of said first valvemember.

3. In apparatus for driving lockbolts and the like which includes ahydraulically operated tool; a control unit comprising a casing, a valvebody mounted on said casing and having an inlet for fluid under pressureand a return to tank outlet, a first valve member mounted in sa d bodyfor movement between two positions for controlling the flow of fluid tosaid tool, a solenoid assembly mounted on said body and connected tosaid first valve member for moving the valve member to one of saidpositions, a second valve member mounted in said body andfluid-communicated with said first valve member and said inlet in onlyone of said positions of said first valve member, said second valvemember communicating with said outlet and being movable to an openposition by a fluid pressure above a predetermined pressure exertedthereon, a pressure relief valve member mounted on said body andcommunicating with said inlet in both positions of said first valvemember, a step-down transformer mounted on said casing, and a solenoidcontrol relay mounted on said casing and operatively associated withsaid solenoid and said transformer.

4. In apparatus for driving lockbolts and the like Which includes ahydraulically operated tool; and a valve body having an inlet for fluidunder pressure and a return to tank outlet and an outlet connectible tosaid tool, a first valve member mounted in said body for movementbetween two positions for controlling the flow of fluid to said tool,means forming a valve seat on said body in fluid-communication on oneside with said inlet, a second valve member movable to a seated positionon said seat, spring means urging said second valve member toward saidseated position, passage means communicating said return to tank outletwith the opposite side of said seat so that the amount of fluid flowinginto said passage means is proportional to the extent of movement ofsaid second valve member in a direction opposed to said spring means,and a pressure relief valve member mounted on said body andcommunicating with said inlet in both positions of said valve member.

5. In apparatus for driving lockbolts and the like which includes ahydraulically operated tool; a valve body having an inlet for fluidunder pressure and a return to tank outlet, a first valve member mountedin said body for movement between two positions for controlling the flowof fluid to said tool, means forming a valve seat on said body influid-communication on one side with said inlet, a second valve membermovable to a seated position on said seat, spring means urging saidsecond valve member toward said seated position, passage meanscommunicating said return to tank outlet With the opposite side of saidseat so that the amount of fluid flowing into said passage means Variesin accordance with the extent of movement of said second valve member ina direction opposed to said spring means, and a pressure relief valvemember mounted on said body and communicating with said inlet in bothpositions of said first valve member.

References Cited in the file of this patent UNITED STATES PATENTS1,987,561 Wiegand Jan. 15, 1935 2,377,278 Stephens May 29, 19452,825,353 Voytech Mar. 4, 1958

